The Constitution is the fundamental law of any state. It regulates its political structure, the powers of the various branches of government, the timing and procedure for their replacement. Also, the constitution clearly defines the rights, freedoms and obligations of citizens of the state, it is indicated how and under what conditions changes can be made to the constitution itself.
It would seem that any sane and capable person should know this basic law, if not by heart (this is hardly possible even for a qualified lawyer), then at least in general terms. In practice, alas, everything is different. Many people do not consider it necessary to study the content of the constitution. The reasons for this are very different: from banal laziness to disbelief that knowledge of the basic law can help in something. We often hear: they say, we are small people, what difference does it make whether we know or don’t know, nothing depends on us! But this is a fundamentally erroneous and even harmful position. Everyone should know their basic law. Very often one has to deal with unscrupulous officials of all levels who try, under one pretext or another, to deny a citizen his legitimate request. Practice shows that if you start talking to them in the language of the law, clearly referring to certain articles, then their behavior immediately changes. Or, suppose you often have to deal with those law enforcement officials from whom these very bodies need to be protected. For example, many Moscow policemen (now policemen) got into the habit of collecting "tribute" from those Russian citizens who do not have a Moscow registration, frightening them to be held accountable for an alleged violation. Practice shows that a decisive refusal, with reference to an article of the constitution that guarantees freedom of movement within the territory of the Russian Federation, immediately discouraged them from seeking "free" money. They preferred not to get involved with a person who knows the laws. After all, any person simply needs to know their rights and responsibilities! At least in order to understand what he has the right to ask (or demand), and what the state, represented by the authorized bodies, can already demand from him. And if a citizen considers that this or that law or normative act is contrary to the Constitution and infringes on his rights and freedoms, he can apply to the Constitutional Court with a claim to declare such a law or normative act invalid, subject to correction or repeal. And there have been such precedents, and more than once.